Dark-brown wool-dye.



NITED STATES Patented August 9, 1904.

PATENT OFFICE.

AUGUST LEOPOLD LASKA, OF OFFENBACI-I-ON-THE-MAIN, GERMANY, ASSIGNOR TOFIRM OF K. OEHLER, ANILIN- & ANILINFARBEN FAB- RIK, OFOFFENBACH-ON-THE-MAIN, GERMANY.

DARK-BROWN WOOL-DYE.

SPECIFICATION forming part of Letters Patent No. 767,069, dated August9, 1904:.

ments in Dark-Brown Wool-Dyes, of which the following is aspecification.

My invention relates to the manufacture of monoazo dyes by combiningsulfo-conjugated diazonaphthalenes with metaoxydiphenylamin. Thesedyestufl's yield on wool dyed in the usual manner and subsequentlytreated with chromic compounds acting as oxidizing agents dark-brownshades of valuable properties.

The process may be carried out both in acid and in alkaline solution.

Example: Diazotize, as usual, 24.5 parts of naphthionate of sodium bymeans of 6. 9 parts of sodium nitrite and forty-six parts ofhydrochloric acid 20 Baum. Then pour the diazo compound into a solution,cooled with ice, of 18.6 parts of meta-oxydiphenylamin in ninety partsof sodium lye of Baum and two hundred parts of water. At the end of thereaction acidulate weakly by adding hydrochloric acid to the solution,then salt out, dry, and finally mix the dyestuff thus obtained with 10.6parts of soda.

The dyestufi forms a reddish-brown powder, dissolves in water with ayellowish red, in concentrated sulfuric acid with a reddishviolet color,and yields on wool when treated Serial no. 202,909. (Specimens) afterdyeing with chromium compounds acting as oxidizing agents blackish brownshades. In a similar manner the combination may be carried out withother mono and di sulfonic acids of the alpha and betadiazonaphthalenes.

Now, what I claim, and desire to secure by Letters Patent, is thefollowing:

1. The process of making monoazo dyes, consisting in the combination ofsulfo-conjugated diazonaphthalenes with meta-oxydiphenylamin.

2. The process of making monoazo dyes, consisting in the combination ofthe sulfonic acids of the alpha-diazonaphthalene withmeta-oxydiphenylamin.

3. As new articles of manufacture the monoazo dyes which result bycombining the sulfonic acids of the alpha-diazonaphthalenewithmeta-oxydiphenylamin,formingreddishbrown powders, dissolving inwater with a yellowish red and in concentrated sulfuric acid with areddish-violet color and yielding on wool when treated. after dyeingwith chromium compounds, acting as oxidizing agents, blackish-brownshades.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

AUGUST LEOPOLD LASKA.

\Vitnesses:

HERMANN WEIL, OSKAR STANDHARDT.

